The present invention, in some embodiments thereof, relates to mechanical supports for bodily vessels, and in particular to devices and methods for deploying implantable sleeves over blood vessels such as peripheral or coronary arterial bypasses grafts.
Coronary heart disease is the leading cause of death in the U.S today. The treatment of choice for patients who suffer from severe coronary artery disease is coronary artery bypass grafting (CABG) surgery. In this procedure, bypasses are built around narrowed arteries, using the patient's native harvested vessels, mainly the internal mammary arteries and the greater saphenous veins. Exposure of the vein graft to high arterial radial pressures is a primary cause of intimal/medial hyperplasia (vessel wall concentric thickening), and as a result, of accelerated atherosclerosis and vein graft failure.
Externally supporting the graft with an external device has the potential to reduce wall stress and cyclic stretching of medial and endothelial cells and reduce diameter mismatch between the vein graft and the artery, all of which might be expected to reduce wall thickening. The efficacy of external support to the graft has been studied by several groups over the past few years and the findings from pre-clinical studies demonstrated significant inhibition of neointimal formation, reduction of atherosclerosis plaques and overall graft thickening reduction comparing to non-supported grafts.
Prior publications describing grafts provided with external supports or layers commonly suggest bonding of the external support to selectively cover the graft, optionally by using glue or sutures. Exemplary publications include U.S. Pat. No. 5,755,659 to Zurbrugg and U.S. Pat. No. 7,998,188 to Zilla et al., the disclosures of which are fully incorporated herein by reference. Such grafts may be provided to the medical practitioners readily covered and supported, or that the medical practitioners or their supporting team are instructed to bond the graft and the external support together prior to grafting. The latter scenario may be time consuming and bothersome to the medical team and may derive special training and expertise in materials bonding and preparations so that the finalized artifact will be satisfactory prepared in a timely manner. Using glue and sutures may also damage the grafted vessel tissue or the grafting procedure and compromise graft patency.